The present invention relates to an ink image-recording element.
In a typical inkjet recording or printing system, ink droplets are ejected from a nozzle at high speeds towards a recording element or medium to produce an image on the medium.
The recording elements typically comprise a support or a support material having on at least one surface thereof an ink-receiving or image-forming layer.
In order to achieve and maintain high quality images on such an image-recording element, the recording element must:
Exhibit no banding, bleed, coalescence, or cracking in inked areas.
Exhibit the ability to absorb large amounts of ink and dry quickly to avoid blocking.
Exhibit high optical densities in the printed areas.
Exhibit freedom from differential gloss.
Have high levels of image fastness to avoid fade from contact with water or radiation by daylight, tungsten light, or fluorescent light.
Have excellent adhesive strength so that delamination does not occur.
While a wide variety of different types of image-recording elements for use with ink devices have been proposed heretofore, there are many unsolved problems in the art and many deficiencies in the known products which have severely limited their commercial usefulness. A major challenge in the design of an image-recording element is laminate adhesion. A typical coating from the prior art comprises a layer containing hydroxypropylmethyl cellulose, hydroxyethyl cellulose and a vinyl latex polymer, a layer of pectin, a layer of poly(vinyl alcohol) and polyurethane, and a layer of lime processed osseine gelatin in the order recited. This formulation has demonstrated poor laminate adhesion. U.S. Pat. No. 6,089,704 discloses an inkjet recording element comprising a support, a hydrophilic image-recording layer and an overcoat layer comprising a vinyl latex polymer further comprising a hydrophobic monomer, a hydrophilic nonionic monomer and a cationic monomer. However, the image quality of this element is often poor. U.S. Pat. No. 6,015,624 discloses an inkjet recording element which has a base layer comprised of a blend of poly(ehylene-co-acrylic acid) and at least one hydrophilic liquid absorbent polymer and an ink transmissive upper layer of methyl cellulose, hydroxypropylmethyl cellulose and blends thereof and an organic acid salt. U.S. Pat. No. 5,567,507 discloses an inkjet recording element which has a base layer comprised of a blend of poly(ethylene-co-acrylic acid) and polyvinylpyrrolidinone and an upper layer which comprises methyl cellulose, hydroxypropylmethyl cellulose and blends thereof and an organic acid salt. EP 1 110 745 discloses an inkjet recording element which has a hydrophilic absorbing layer comprising gelatin or poly(vinyl alcohol), a laminate adhesion promoting layer comprising pectin or alginate and a hydrophilic overcoat layer comprising hydroxyethyl cellulose and blends thereof and an organic acid salt. These inkjet recording elements, as disclosed, demonstrate inadequate laminate adhesion. JP 8267905 discloses an inkjet recording sheet that has an electron beam hardened inner layer composed of polyvinylpyrrolidinone, an aqueous electron beam hardening compound and an electron beam hardened outer layer containing poly(alkylene oxide) water soluble macromolecules and, as needed, an aqueous electron beam hardening compound on the support. U.S. Pat. No. 6,110,585 discloses an inkjet recording element with a support, and upper and lower layers separated by a layer, intended to control ionic interactions between the upper and lower layers, containing a nonionic or amphoteric material which is compatible with colloidal silica such as poly(vinyl alcohol), polyvinylpyrrolidinone, polyacrylimides, poly(alkylene oxides), gelatin and derivatives and combinations thereof.
It is an object of this invention to provide an ink recording element which has excellent image quality, less differential gloss, and better laminate adhesion than the elements of the prior art.
These and other objects are achieved in accordance with the invention which comprises an ink recording element comprising a support having thereon a hydrophilic absorbing layer, a laminate adhesion promoting polymer inner layer, and a hydrophilic overcoat polymer layer.
In accordance with the invention, it has been found that a specific combination of image receiving layers, each comprised of specific materials and arranged in a specific sequence on a support material, yields excellent ink imaging performance for a wide range of commercially available printing systems, especially with respect to image quality, differential gloss, and laminate adhesion.